Apparatus for exciting- roentgen-ray tubes



F. RIEBER. APPARATUS FOR EXCITING ROENTGEN RAY TUBES. APPLICATION HLED JAN. 29. I9H.

1,305,495. Patented June 3, 1919.

WITNESSE I I INVENTOR.

' F'fifl/V/I 9/555 J MM M H/S A TTOR NE Y6 4 UNITED STATES PATENT onrron.

FRAN K RIEBER, OF SAN FRANCISCO, CALIFORNIA, ASSIGNOR, BY MESNE ASSIGNMENTS, 1'0 BIEBER LABORATOBIES, OF FRANCISCO, CALIFORNIA, A CORPORATION OF CALIFORNIA.

AFFABATUS FOB, EXCITING ROENTGEN-RAY TUBE S.

J Specification of Letters Patent.

' Application and January 29, 1917. Serial No. 145,088.

To all whom it may concern:

Be it known that I, Fnnmr Rrscnn, a citi- Zen of the United States, and a resident of the city and county of San Francisco and State of California, have invented certain new and useful Apparatus for Exciting Roentgen-Ray Tubes, of which the following is a specification.

The invention relates to apparatus for producing high tension unidirectional cur ing t e operating characteristics of the apparatus during such alteration. The excitation of Roentgen tubes by socalled interrupterless or transformer type outfit has heretofore been controlied in one of two Ways. apparams heretofore used the said interrupter-less apparatus consisted primarily of a source of aiternating potential, a transformer adapted to increase the potential of said aiternatiug source to a point where it may be applied for the production of Roentgen-rays and means for converting this high potential alternating current into high potential direct current.

The controlling means used for varying the power and potential applied to the Roentgen tube consists either of a resistance or rheostat mserted in series in the primary circuit of the high tension transformer aforesaid or of an auto-transformer or other device receiving the input or line alternating potential and deliveringa potential which may be varied and which is applied-to the primary terminals of the high tension transorme . Auto transformers or controls of this lastdescribed class, have a distinct advantage in that they have low inherent electrical imedance and therefore supply an approximanly uniioim alternating potentia indspective of the total load imposed upon the apparatus by the Roentgen tube. As heretofore constructed, however, these auto transformers have thedistinct disadvantage that the flow of current through the apparatus mustbe interrupted during the time that the potential delivered from the autotransformer is being varied.

Patentedv June 3, 1919.

By the apparatus of my invention this dev feet is obviated and it becomes possible to make any desired alteration in the potentlal delivered fromthe auto transformer (said.

alteration causing a corresponding alteration in the high potential delivered from the high tension transformer) without interrupting the flow of the current.

In the accompanying drawings 1 have illustrated an embodiment of my invention in diagrammatic form, but it is to be understood that I do not limit myself to the embodiment shown, since the invention as set forth in the succeeding claims" may be embodied in a plurality of forms. Referring to said drawings: Figure l is a diagrammatic representation of the apparatus of my invention.

Figs. 2, 3 and 4 are diagrammatic repre-i sentations of different positions of the potential changmg contacts of the apparatus.

Fig. 5 is a diagrammatic representation of one arrangement of the auto transformer terminals and means for moving the potential changing contacts over them.

The winding 2 of the auto transformer is connected at itsends to power leads 3-4.-

which extend to a suitable source of alternating potential. The Winding 2 is provided at one end with a common terminal 5 and at spaced points along the winding with taps which are connected to the plurality of spaced terminals 6789, etc,, so that a variable electromotive force may be obtained by shifting a contact from. one terminal 678 9, etc., to another. The terminal 5 is connected to one side of the primary winding 12 of a high potential transformer 13 and the other end of the primarywinding is mediately connected to one of the terminals 6789, etc, the potential between the terminal 5 and the chosen terminal 6- 789 being delivered to the primary winding. A voltmeter 14 may be rovided for. measuring the delivered potental and a switch 15 may be provided for conveniently interrupting the circuit when desired. The

secondary winding 16 of the transformer delivers alternating current at high ,otentials to a suitable rectifyin device 1 and the unidirectional current t erein produced is conducted to the Roentgen-tube 18. v

Means are provided for varying the po-' tential delivered fromthe auto transformer without interrupting the current through the tube. I Arranged between the terminals 67.-89 and one side of the primary transformer winding 12 is a small transformer winding 21 which is connected at its center to the end of winding 12 and which is provided on its ends with contacts 2223 which slidably engage one or two of the therefore becomes zero. The voltage deliv-.

terminals 6789 at one time. In Figs. 2, 3 and 4: I have shown the small transformer contacts in different positions with respect to the terminals 6 and 7, illustrating the method of varying the potential delivered from the auto transformer without interrupting the current. In Fig. 2, the con-' tacts 22 and 23 are in engagement with the terminals 6 and 7 respectively. In this position the current flows from terminal 6 through the small transformer winding 21 to terminal 7, thereby exciting the smalltransformer. The central terininal 24 on the small transformer will then have a potential midway between the potentials of terminals 6 and 7 and this potential is effective in the winding 12. By moving the contact 22 out of engagement with terminal .6 and allowing contact 23 to remain in engagement with contact 7, the current will flowto the winding 12 through one path ofthe small transformer. In this position, the inherent impedance of the small transformer is interposed in the circuit, but with proper construction, this is so slight that the alteration of the operating characteristics of the apparatus is inappreciably small.

In the position shown in Fig. 4, both contacts 22 and 23 are in engagement with terminal 7, so that one-half of the current passeseach way' through the small transformer, the resultant impedance of which ered from the auto-transformer has, therefore,.been varied without interruptin the flow of current and without appreclably altering the operating characteristics of the apparatus during such variation.- The movement of the contacts 2223 may be continued throughout the entire range of the terminals 6-78.-9, etc., of the auto transformer in. order to obtain the desired potential at the tube. v

In practice, the terminals 6-,7-8'9, etc., may be arranged in an arc and the contacts 2223 carried on an arm 25, so that by rotation of the arm, the contacts and terminals will assume successively the positions indicated in Figs. 2, 3 and 4.

I claim: 2 1. In an apparatus for producing high potential unidirectional electrie.current,- a

source of alternating potential, means for transforming said potential to another potential, means for varying said transformed potential without interrupting the conti nuity of the electric current, means for transforming the variable potential to a much higher potential, and means for converting the resultant high potential alter high potential unidirec-' nating current to tlonal current.

2. The combination with a Roentgen ray tube, of a circuit therefor, an auto-transformer in said circuit having a plurality of taps and a subsidiary auto-transformer having end taps in movable engagement with said first mentioned taps, said -sub-' sidiary auto-transformer being connected in said circuit and said end taps being arranged so that the voltage of the circuit may bevaried without opening the circuit.

-3. In an apparatus for producing high potential, unidirectional current, a source of alternating current of substantially constant potential, means having inherently low. im

pedancefor transforming said potential to a diflerent potential, means for varying the transformed potential without interrupting the continuity of the electric current, means for transforming the resultant potential to a higher potential and means for converting high potential unidirectional current.

4. In an apparatus for producing high potential unidirectional current, a source of alternating current of substantially constantpotential, an auto transformer in circuit with said source, a plurality of taps on said auto transformer, a high potential transformer having its primary connected at one side to one side of the auto transformer and at the other side to said taps, a small transformer interposed between said primary and said taps and having the center of its windvthe higher potential alternating current to Y ing connected to said primary and'th'e ends .of its windings movable into contact with the successive taps a secondary for said high tension trans ormer and means connected to said secondary for convertin the high potential alternating current to igh potential unidirectional current. v

5. .In an apparatus for producing high po-. tentialunidirectional current, an auto trans former having a plurality of taps, terminals connected to said taps, a small transformer havingthetwo ends of its winding movable i in contact with said terminals,a' high potential transformer havin its primary connected to said auto trans ormer and .to the .middle of said small transformer winding and a current-converting device connected to the secondary of said high tension transformer.

I 6. The combination with a source of alternating current potential of an auto-transformer in circuit with said source, a plurality of taps on said auto-transformer, a

small auto-transformer having the ends of its winding movable into contact with the successive taps and a circuit connecting the center of the small transformer winding 

